Manufacturer description: The new Tokina AT-X 535 PRO DX lens is a 50-135 with a fast constant aperture of f/2.8. This lens gives digital photographers the similar to the industry standard 80-210 telephoto zoom lens in 35mm camera terms but is much more compact and lightweight. The lens features SD glass lens elements to correct for chromatic aberrations and focuses all colors accurately at the film plane, making the AT-X 535 PRO DX an APO lens. The front element has a newly formulated WR or “Water Repellent" optical coating on the glass.Manufacturer Description: